Day 2: Understanding Technical Video Conference Terms

First things first, on our journey here to understand the technical aspects of videoconferencing. Definitions! This is an area where there is a lot of confusion in K12 education.

IP Videoconferencing

This is an ambiguous term. “IP” just means Internet protocol. It just means that you’re using the Internet. Some people used to use this term to differentiate between IP (over the Internet) and ISDN (digital phone lines) videoconferencing. But now, most videoconferencing is over the Internet. Whether web based, software based, hardware based, videoconferencing generally connects over the Internet. So the more useful terms are exactly HOW are you videoconferencing. What software or hardware are you using and does it use a standard?

H.323 Videoconferencing (Standards-based)

The videoconferencing we use is standards-based. That is, whether you are using Polycom, Tandberg, LifeSize (etc) equipment or software, you can connect to any other equipment or software that is also using the H.323 standard. Most of the content providers we connect to, the content that Whirlidurb offers, and the collaborations and events in CAPspace all use the H.323 standard .

Skype, Windows Messenger, Google Chat, TokBox, etc.

Each of these videoconferencing tools is “proprietary” software running on a computer with any type of webcam. You can only connect to the people using the same software or web application.

Desktop Videoconferencing (can be standards-based or proprietary)

Desktop videoconferencing is also known as software-based videoconferencing. You need:

  • a computer
  • a webcam
  • videoconference software

In a classroom, desktop videoconferencing can be used for the whole class by connecting the computer to a projector.

Desktop videoconference software options include:

Hardware-based Videoconferencing (standards-based)

Many schools install videoconference carts, with a videoconference appliance. This “box” is also known as:

  • the codec
  • the endpoint
  • the camera

Carts installed in schools usually include:

  • A camera
  • The codec (the “box” that has all the smarts to make VC happen)
  • A microphone
  • A display – often a 30-50 inch LCD monitor or a projector
  • A document camera
  • A way to connect the computer
  • A remote for video conference unit

Bridge (only standards-based)

Some large school districts and many educational service agencies have additional videoconferencing equipment: the “bridge” or MCU (multipoint control unit).

  • A bridge allows for multiple videoconferences (aka conference rooms) at the same time
  • A bridge allows two or more videoconference sites or endpoints to connect into the same conference
  • A bridge allows multi-vendor endpoints to co-exist in a conference


For further reading, see these resources:

Your Turn

  • Do you know what kind of videoconferencing you have? Is it standards-based (H.323) or not?
  • If you use desktop videoconferencing, what kind are you using? Who can you connect to?

Knowing this will make it easier to connect to other educators!

Team-written by Janine Lim, Shane Howard, and Roxanne Glaser. The opinions expressed in these posts are based on our collective video conference experience connecting classes across multiple networks to connect them to zoos, museums, experts and other classes during the past 10 years. This series of posts reflects our usage and understanding, not that of any vendor or manufacturer. No one is paying us to write these. We are just sharing what we have learned.

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